Robustify facilitate(RangedSummarizedExperiment)

I ran into all sorts of problems when running `facilitate()` on the RangedSummarizedExperiment from the airway package.

rowData wasn't being set, rownames lost, etc.

Follow up with the comments in `facilitate.SummarizedExperiment()` and make sure our solution is robust. Right now it's rather hacky.
